bench: use %f instead of %lf
bench: use %f instead of %lf

While %lf is legal, it's redundant.

Change-Id: Ic97fbe10c050846dd389d5c6d4f9de6d20d6c3a4
Reviewed-on: http://review.couchbase.org/51282
Tested-by: buildbot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Dave Rigby <a09264da4832c7ff1d3bf1608a19f4b870f93750@couchbase.com>

mnunberg/subjson,mnunberg/subjson